I’ve had some success and a tiny bit of failure, so here I am.
I managed to get the switch and driver out. In the process I lost the tip off a dental pick. All in all, a fair trade I think.
The tools I used: A pair of weird, long needlenose with rounded tips, a dental pick, and a medium-stout S hook.
A little bit of careful convincing with the needlenose and the switch ring came right out. Holding them square and keeping outward pressure on the jaws made it fairly easy. Tip - try rotating the light instead of spinning the pliers.
Now came the fun part - getting the button itself out. I could only get a little purchase with the pick at the bottom of the board, and on one edge where there was a little divot out of the board. Some careful prying (and the sacrifice of the fine tip of the pick) and the switch was out.
Now it’s time for the scary part. Blindly jamming bits of metal into its brain. From the threads linked to above, I knew that the only things under the switch were soldered wires. Don’t be an idiot and things should be fine. (Side note - while the shape might be right, one of those disposable plastic dental floss sticks is nowhere strong enough to pull this off)
I straightened one side of the S hook a bit, put in in the hole, being careful to not pinch the switch wires, and gently pressed. Then I pressed some more. This was followed with some mild swearing, a little more pressure, then a pop.
I cleaned some glue off the driver to make reinstallation and subsequent re-dissassembly easier, then put it back together to make sure I hadn’t broken anything. And It Still Worked!
Now I’m off to find the programming tools I’ll need. Lets see… USBASP, some wires, that weird 8 pin clampy thing, etc.
I must be broken. I’m sitting here wondering how I could make some holes in the driver to pass wires and glue a pogo-pin contact to the battery side. 